Line-narrowed and line-selected excimer and molecular fluorine lasers can be used advantageously in industrial applications such as optical microlithography for forming small electronic structures on silicon substrates. Photoablation and micromachining applications require these lasers to be run at medium to high power, while maintaining a necessarily high repetition rate. Problems exist for such high repetition rate laser systems, however, as there is an unacceptable risk of arcing in the discharge chamber. Several approaches have been taken to improve the arrangement and composition of components in such a system, but none have proven to provide acceptable performance with an ease of use and at a reasonable cost.